According to The Jerusalem Post story published on April 23, 2013:
Israel Aerospace Industries Ltd. (IAI) will build wings for the F-35 Lightning II stealth combat jet, which Lockheed Martin Corporation will begin producing in 2015. The 10-15 year contract has a potential value of $2.5 billion.
IAI and Lockheed Martin have begun setting up the production line for the F-35’s wings at an IAI facility.
IAI will invest in state-of-the-art technologies and systems needed for the project.
“The F-35 is an important milestone for IAI, and guarantees the company’s involvement in advanced combat aircraft. I welcome the strengthening of the ties with Lockheed Martin,” said IAI CEO Joseph Weiss.
http://www.jpost.com/Breaking-News/IAI-to-build-F-35-wings-for-Lockheed-Martin-310787